Device for case-hardening axle-boxes



(No MbdeL) J. W. PARMELEE. DEVICE FOR CASH HARDENING AXLE BOXES.

Patented May 7 .w W 6 WM 3 a? w M n. nuns mmumn n m. wgahingfon. n.c

UNITED STATES PATENT OFFICE.

JOHN PARIWIELEE OF WILKES-BARBIE, PENNSYLVANIA.

DEVICE FOR CASE-HARDENING AXLE-BOXES.

SPECIFICATION forming part of Letters Patent No. 402,964, dated May '7, 1 889.

' Application filed March 8, 1888. Serial No. 266,573. (No model.)

To all whom it may aoncerm.

Be it known that I, JOHN W. PARMELEE, a citizen of the United States, residing at WVilkes-Barr, in the county of Luzerne and State of Pennsylvania, have invented a new and useful Improvement in Devices for Case- Hardening Axle-Boxes, of which the following is a specification.

My invention relates to an improvement in devices for interiorly case-hardening axleboxes; and it consists in a pair of caps which are adapted to close the ends of the axle-box, so as to leave the ends of the latter exposed to the action of the gas while the axle-box is being case-hardened, as will be more fully set forth hereinafter, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a perspective view of an axle-box provided with end caps embodying my improvement. Fig. 2 is a vertical longitudinal sectional view of the same. Fig. 3 is a detail pespective view of the cap.

A represents an axle=box, of the usual form, which is provided at its inner end with the enlarged portion B, to receive the collar or flange at the inner end of the axle-spindle. The outer end of the axle-box is slightly tapered, as at O. This axle-box is made of wroughtiron, and it is highly desirable to case-harden the inner surface thereof and convert the same into steel, so as to prevent the axle box from wearing too rapidly by frictional contact with the spindle and to leave the exterior surface of the axle-box unchanged, so that the axle-box will be composed of wrought-iron and will haveits inner surface of steel. In the process now employed for thus case-hardening the inner surface of the axle-box the same is filled with animal charcoalsuch as ground bone or with other suitable material-such as sand mixed with cyanide of potassium. The ends of the axlebox are closed by means of plates, and the same is then placed in a heating-furnace and subjected to a suitable heat for from two to three hours, when the gases generated from the bone or cyanide of potassium will have converted the interior surface of the axle-box into steel. As soon as the axle-box is withdrawn from the fire the packing is run out and the box is plunged into a bath of water.

The object of my invention is to provide suitable caps for closing the ends of the axleboX, so as to retain the ground bone or other material therein, together with the gases as they are generated, and to expose the extreme ends of the box to the action of the gases and to permit the superfluous gases to escape and prevent them from blowing off the caps. These objects I accomplish by the caps hereinafter described.

E represents a circular cap, which is made of cast-iron, fire-clay, or any other suitable material, and has an interior diameter sufficient in size to enable the cap to be placed on the enlarged inner end of the axle-box. The inner side of the said cap is slightly tapered, as shown, so that the said cap cannot be forced directly in contact with the inner end of the axle-box, and thereby the inner endof the axle-box will be exposed to the action of the gases.

F represents another cap, the exterior diameter of which is equal to the exterior diameter of the cap E. Said cap F is provided on its inner side with a central recess, G, of sufficient diameter to receive the tapered outer end of the axle-box, the taper of said box being such as to prevent the said cap F from coming in contact with the extreme outer edge of the axle-box, and thereby said. outer end of the axle-box will be also exposed to the influence of the gases. In order to prevent the gases from accumulating in the axlebox to such an extent as to force off the caps by their pressure, I provide the caps each with a small central aperture, H, through which the superfluous gases escape.

By thus adapting the caps to expose or uncover the extreme ends of the axle-box the said ends of the axle-box, as well as the interior surface thereof, are exposed to the action of the gases and are converted into steel.

It will be observed that when the axle-box is tapered the caps need not have a tapered recess; but whennot tapered it is essential that such tapered recess be provided inthe capsin order to prevent the caps from closing up against the ends of the axle-box.

I do not wish to confine the use of my invention to axle-boxes, as the same may be applied in the manufacture of other articles of an analogous nature.

Having thus described my invention, I clain1 1. In combination with an axle-box or the like, the recessed caps adapted to fit over and close the ends thereof, the caps having their recesses tapered so as not to come directly in contact With the ends of the box, for the purpose set forth, substantially as described.

2. In combination with an axle-box or the like, the cap E, having the tapered recess in its inner side adapted to fit over the enlarged end of the aX1e-boX, and thereby prevented from coming directly in contact with the extreme inner end of the axle-box, and the cap F, having the recess G on its inner side adapted to fit snugly on the tapered outer end of the axle-box, said cap being provided with the openings II, substantially as described.

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in 20 presence of two Witnesses.

JOHN \V. PARB'IELEE.

fitnesscs:

S. (J. S'rno'rnnns, FRANK. \V. PARMELEE. 

